Brad Plumer opines that there is a compelling argument that the world ought to be building many more nuclear power plants. He agrees that we will need vast amounts of carbon-free energy to stave off global warming. It is not at all clear that renewables can do the job alone for a number of reasons. And nuclear is a proven technology, already providing 11% of electricity globally.

So what is the catch, Plumer asks? Cost. More than safety or waste issues, modern-day reactors have become jarringly expensive to build, going for $5 billion to $10 billion a plant. Worse, the price tag seems to be rising in many places. Back in the 1960s, new reactors in the U.S. were one of the cheaper energy sources around (Not !!, even expensive then). 3 decades later, after a series of missteps (what?), costs had increased sixfold, a big reason we stopped building plants, all driven by excessive federal and state regulations and by differing reactor designs. But all have been been built to last for 80 years, like many hydroelectric dams.

But Plumer also suggests that there is also an optimistic story for nuclear ... one that he thinks has merit. A recent paper in the journal Energy Policy by Jessica Lovering, Arthur Yip, and Ted Nordhaus of the Breakthrough Institute looked at construction costs for hundreds of reactors built in the U.S., France, Canada, Japan, German, India, and South Korea between 1960 and 2010. Their data tell a more interesting story.

Nuclear construction costs in the U.S. did increase, especially after the Three Mile Island incident in 1979. But this was not universal. Countries like France, Japan, and Canada kept construction costs fairly stable during this period. And South Korea actually drove nuclear costs down. Studying these countries can offer lessons for how to make nuclear cheaper so that it can further expand in the U.S. and around the world to replace coal and eventually natural gas.